Thermal Optimal Analysis And Study Of Trombe Wall Based On Energy Demand

The academic circles and society is paying highly attention to solar building because it is in a dominant position of energy saving and environmental protection. Trombe wall is widely used as one of the main forms of the passive solar house with the functions of collecting and storage heat, thermal insulation, also advantaged in simple structure, steady thermal stability. The existing researches are mainly about the Trombe wall thermal performance, but for the thermal characteristics under the influence of whether used insulation layer, the location in the wall structure is barely involved. Different thermal insulation and wall materials brought the significant changes in heat collection and storage characteristics, which led to the differences effect in conduction and convection heating. And according to the adaptability analysis about different insulation structure forms of trombe wall for different typical meteorological areas, room energy demands are rarely touched.Based on the theoretical analysis of Trombe wall thermal performance, a simplified simulation model was built for Trombe wall system using numerical simulation and experimental verification, by which the dynamic thermal performance under varied insulation structures and materials, dynamic thermal in four typical meteorological areas about Trombe wall collecting and storage heating characteristics can be accurately described. Then through analysis the simulating thermal environment of Trombe wall type solar building, coupling the study of Trombe wall thermal characteristics and solar thermal environment, obtain the influences of indoor thermal environment under varied insulation structures. The results of the study show that:(1) The external-insulation form which is sensitive to solar radiation has the highest daytime convection heating supply of short duration. While the non-insulation form and internal-insulation form is similar in convection heating pattern, advantaged in thermal storage, distributing the convection heating evenly and last longer.(2) The convection heating of the external-insulation form Trombe wall is greater than the conduction heating supply in one period, while the others are on the contrary. The external-insulation form Trombe wall sets the highest thermal efficiency than others. The key to improve the thermal efficiency of Trombe wall is enhancing convection heat transfer in air layer.(3) The heat collection and storage characteristics of non-insulation and internal-insulation form Trombe wall are greatly affected by the thermal properties of wall materials, while the external-insulation form are not. High thermal conductivity material is conducive to the wall heat thermal storage conduction to the interior, large heat capacity is advantageous to heat accumulation effect to the wall. But at the same time, the high thermal conductivity decreases in wall insulation performance, also reduces the heat convection effect.(4) The typical areas as Lhasa, all kinds of insulation structure of Trombe wall can meet the thermal comfort limits, the external-insulation structure of Trombe wall is easily lead to indoor air over-heat in the daytime, therefore it is inadequate in the daytime-used room.(5) Xi’an or Xining area, the internal-insulation form Trombe wall meets the demand of daytime-used room, auxiliary heating are needed in other time. A continuous heating room is more suitable for non-insulation Trombe wall, so as to avoid the external-insulation form is easy to occur over-heat during the daytime.(6) In Gangcha, it is the best to choose the external-insulation form which sets the highest thermal efficiency, and the other times when do not meet the requirements of indoor thermal comfort need the auxiliary heating.